Transcriptional profiling of endothelial cells lacking Flvcr2

Flvcr2 is a putative heme transporter expressed in endothelial cells of the brain. Mutations in this gene in humans is the cause of Fowler syndrome, in which newborns show malformed brain blood vessels. We generated a mouse model of this disease by knocking out the mouse ortholog of the gene (Flvcr2). These mouse mutants recapitulate the human phenotype. To understand the molecular changes associated with Flvcr2 deletion, we defined the transcriptional profile of heterozygous and mutant endothelial cells. We observed changes in gene expression consistent with altered angiogenesis and metabolic pathways necessary for endothelium homeostasis. Overall design: Endothelial cells were isolated from E14.5 embryonic brains using fluorescent-activated cell sorting. Since the mutation in the Flvcr2 gene leads to expression of GFP, we sorted GFP+ CD31+ cells. Total RNA was extracted from 2000 – 5000 cells to synthesize PolyA+ libraries for sequencing in a HiSeq4000 using SE50. More than 40 million reads were obtained for each sample.